1. Field of the Invention
The present invention relates to an adaptive media encoding and decoding equipment, for dynamic image data or voice data or the like, which is suitable for use with Internet or the like.
2. Description of the Related Art
Conventionally, a dynamic image (or a media) transmitting system having a control which suppresses network convergence in a Cable Internet has been developed. Further, in the dynamic image transmitting system, a system, using a transport protocol with an incoming confirmation and resending function such as TCP or the like, has been proposed.
When packet telecommunication is carried out regardless of whether communication is by cable or radio, data incoming fluctuations arise in the data reaching the receiving equipment due to retransmission by a packet loss or the like. In order to absorb the data incoming fluctuations, a receiving buffer is provided in the receiving equipment. Tolerance of the receiving buffer with respect to data incoming fluctuations becomes stronger, the more the data are stored initially.
Further, when the packet loss is extremely large or the like, the throughput of the receivable data is low, and there is a fear that incoming of the data will not be in time for the decoding at the receiving side. At this time, usually, in order to suppress network convergence, control to reduce the bit rate of the video is carried out. Further, at this time, control is carried out such that stable operation is carried out when the duration time of the contents is very long.
The tolerance of this receiving buffer with respect to data incoming fluctuations becomes stronger, the more the data are accumulated initially. However, on the other hand, there are problems in that it takes much time from the start of receiving until much data is accumulated, and it takes much time until the start of playback of a dynamic image or music.
As described above, in order to smoothly carry out decoding at the receiving side, the system is controlled so as to operate stably when the duration time of the contents is very long. However, for example, considering services directed to cellular phones or the like, the duration time of the contents is relatively short. Therefore, there is a problem that a case in which the duration time of the contents is relatively short is not given any consideration in the conventional system.